sludge tube removal

[RDfella]

One for the 'check your sludge trap' platoon.
Pulled the engine (A10 GF) out today ready for new conrods etc. Thought I'd better look into the so-called sludge trap (it's my opinion that collecting sludge was just an unwanted side-effect of a bad design) because when I rebuilt the engine previously I couldn't get the plugs out and so gave it a miss.
This time, I approached it with violence in mind. Got the drive side (hex plug) out without too much bother and then turned my attention to the timing side - the one I couldn't remove before. Nor this time. It's the slotted type. Tried an impact driver - no chance. Tried heat and impact driver - it moved a fraction. Trying to drift it was a waste of time, so thought I'd drill it - you know, like you read on the internet 'just drill it and use an easy-out'. Well, they can come and drill mine, because it's glass hard. An ordinary drill bit glides off it and a carbide burr struggles to make an impression. So I welded a 9/16 AF nut to it - with some trepidation, as there ain't much room and didn't want to weld it to the crank. With a long bar on a socket, the nut tore in half.
Thought about using carbide drills (assuming they'd cope) but they're brittle and the last thing I need is more grief with a broken drill stuck in there. And so I've ground it all flush and that's how it's going to stay. Had my mate George still been alive, I'd have used his spark-erosion machine - but he isn't and so I can't.
Which leaves me with a question - can the tube be pulled out with one plug still in place? It's not full of crap in there, but I do see some sludge between tube and crank.

[muskrat]

G'day RD
I had similar problem with both sides (slotted type) a few weeks ago. Broke 4 impact bits! In the end I vigorously heated the area around and with two more bits they moved.
I would have thought the heat from the weld would have done it but the heat would have been mostly on the plug expanding it.
The plug shouldn't be that hard. I'd re-visit the carbide drill (masonry drill sharpened like a normal drill) method.
I think the tube only comes out the timing side.
Cheers

[CheeserBeezer]

I think the tube will come out either side. The 'bell-end' (oh dear!) is on the timing side but I'm pretty sure the oilway is parallel. You might be able to unscrew the centre locating bolt and drag it out with something hook shaped. Both the plugs are the same thread so I don't see any reason why it won't come out from the main bearing side. Good luck!

[Swarfcut]

 A diamond hard plug certainly presents a problem for  two basic approaches. Sticking something on the outside to take a drive, (the old weld a nut or lug on), or the drill a hole/drill it out way.

 Certainly the weldanut method carries the risk of welding the whole ensemble together, but I have had good success with a quick dab down a big nut with an arc welder followed by a bit of oxy heat to the web in stubborn cases. This may be the only way in this case if the plug defies any cutting agent readily to hand to penetrate the surface.

 For a less defiant example the other choice would be to drill. I have invested in cobalt drill bits, but found them to be of no real advantage (or else the only cobalt in them was the pack label). A grind of the surface with a Dremel, to break the surface  then a  new high speed steel drill, good and sharp, small size then working up to a larger size to take a TORX bit hammered in, plus heat, worked better than the traditional Easy-Out.  Otherwise once the hole is getting big, the inevitable result of too many futile attempts, it's time to weaken the plug with a junior hacksaw blade and collapse it inwards, with as much controlled violence as it deserves.

  Swarfy.

 

[RDfella]

The real problem, as Swarfy alludes to, is the hardness of the plug. I'd doubt a file would touch it - certainly an HSS tool bit just glides off and even a tungsten burr makes little headway. Why / how it is so hard I'm not sure - perhaps my heating of it in an attempt to free it up hardened it?
Anyway, it is what it is. The weld a nut on failed and I'm reluctant to go further.  I have carbide drills (as well as the good old standby of sharpening a masonry drill as Musky mentioned) but carbide doesn't like interrupted cuts - and the first obstacle is the deep screwdriver slot. Maybe the plug could be drilled from behind, but what then? Would an easyout (modern square type, the LH screw type are useless) actually grip something that hard? What if I'm left with parts of a plug that I can't remove by the usual hacksaw / chisel method? I could burn a hole through with my oxy/acetylene cutter, but then I'm still back at 'what if I can't get the rest out'? I'm also mindful too much heat could distort the crank. Yesterday I'd spent that long heating the plug and trying impact drivers / punches that virtually the whole crank was smoking hot.

This afternoon I'm going to try getting the tube out. If that won't co-operate I may, depending on mood, try a diamond burr to open the plug's slot ready for a shot with a carbide bit.

That old phrase 'everything in my favour is against me' is getting worn thin around here. My son says with such lousy Karma I must have been a terrible person in a previous life.  Maybe he's right. All I know is, at times struggling with seemingly never-ending issues gets me down.

[berger]

RDfella you could well have toughened it up with the heat and cooling process but i have every faith in you mastering it. i am a lot younger than you and sometimes get very frustrated at problems going one step forward and ten backwards, but as my dad used to say " don't let it gaffer you"

[sean]

I havent  had one that wouldnt come out YET  but if they wont come out the regular way on the slotted type I weld a large flat washer to the plug through the hole in the washer then a nut to the flat washer and turn it out with a wrench .....a 3/8th extension will fit into the bell end of the sludge trap tube and after removing the centre bolt and end plugs you can insert the extension into the tube and tap it through

[Black Sheep]

With a stuck slotted head plug, I was able to chain drill a series of holes down through the slot until the plug was almost cut in two but avoiding the threads. I than hammered in a chunk of steel strip (cut to size tyre lever if I remember) and was with some grunt able to unscrew the plug. You begin to wonder if they were ever meant to come out or were we just meant to buy a newer model every couple of years.   

[RDfella]

My luck, like the weather here, was good today. Makes a bloody change. The tube pulled out by pulling on a piece of welding wire hooked in the end hole and jiggling the tube with the handle of a pry bar. Only slight crud on the outside of the tube.
I note the bell end (no, not the crankshaft designer, but the other end of the tube) was at the timing side end. Presumably that was / is correct? I noted too that the belled end is about half an inch away from the recalcitrant plug, meaning the tube is located solely by the flywheel bolt and blanked off by the driveshaft end plug. The purpose of that tube completely escapes me, but overall it is an appalling design. Many (multi-cylinder) cranks have a hole through the centre of a crankpin for balance purposes, but one does not feed oil through it! All that does is deny the big ends oil for a while after start up, whilst the void is filling up. 
The way the flywheel is attached is another example of bad engineering practise. The bolts cannot possibly hold the flywheel to the crank, as the flywheel is essentially un-compressible. The flywheel should have been mounted with axial bolts, not radial ones. I believe Triumph cranks are like that. Locating on the diameter means an unnecessary degree of accuracy - tolerance required maybe as little as .0002" whereas flange mounting would allow tolerances of several 'thou'. BSA supposedly had great engineers, so how did rubbish like this get designed? 

Maybe useful to others with plugs that refuse to budge is the fact you only need one plug removed to get the tube out and clean inside.

[groily]

I believe Triumph cranks are like that. Locating on the diameter  . . . 

Think you're right on Trihards' advantage there RD and that the criticism is fair. Not really a 'rant'!
Did an engine for a friend a few years ago, an early  '50s 5T with white metal (régule I think they call it round here), and it was indeed 'axial' and flanged and not that hard to put back together using new fasteners. Only Tri I've ever done from first principles as in  'split the crank and start again', but it was smooth as silk when rebuilt - with no special efforts or skills applied  . . . . those Trihard cranks might look like a bit of bent wire compared to some others, and the piston oil pumps might not find favour with everyone, but the overall concept seemed to me to be pretty OK when the job was done and the thing was working. Still going like a Swiss watch in different hands 10 years later, last I heard.

[CheeserBeezer]

...................... The purpose of that tube completely escapes me,......................................

You will see that the tube is located in position at three points, 1 - by its bell end which is required to be a snug fit in the oil chamber, 2- by the centre crank bolt, and 3- by the locating nose on the left hand plug. All three locations are required to be oil tight so that the pressurised oil is directed into the tube, not straight into the oil chamber. The oil exits the tube via the holes opposite the centre mounting hole, passes into the oil chamber, then into the big ends. The purpose of the tube is to trap sludge and debris by centrifugal force. When the crank is spinning the sludge travels to the outer edge of the tube, i.e. where the crank bolt is fastened.  The oil exits via holes facing inwards, i.e. opposite to the centrifugal effect. Over time the heavy debris trapped by centrifugal force will build up in the tube and many of us have experienced tubes which are completely full, indicating that the tube has done its job, but the bike was overdue an overhaul. Problems arise when people don't understand that the tube must fit well at all locations for it work properly. Inevitably, a little bit of careful measuring and fettling is required. I drill the ends of the tube to smooth out the hole and alter the noses of the plugs on a lathe to make sure they close the hole off properly.

[Greybeard]

Previous design had no tube

[trevinoz]

I think that you will find that Triumph also went to the radial bolt crank.

[Swarfcut]

 A timely reminder there from CB that the tube must be removed to completely clear the sludge. My 1960 model bought as a basket case had the crank ground twice in quick succession and the owner was puzzled why the motor tightened up and wiped out the big ends again. Removing the end plugs, he'd just cleaned through the tube, little realising that true miscreants were hiding behind the curtain, so to speak.
  The diagram does not tell the whole story, large particles will stay in the tube, smaller ones will pass from the tube into the space between the tube and the crank cross drilling (the oil chamber) and be forced first to the outside by centrifugal force, in the opposite direction to the oil flow to the big end journals, gradually accumulating until the chamber is full of sludge, severely reducing the oil flow. With the tube removed, these pesky devils can be exposed and sent on their way.

 Accepted wisdom is that the radial bolt should be replaced with a new one, and the thread needs to be oil tight, so some locking compound is necessary, but with the variable quality and unknown source of even branded replacements, at least you know the metallurgy of the original was correct. So, take your choice. The locating nose on the bolt will obstruct the tube if too long.....or the body of an aftermarket tube is bigger than it should be.

 Flywheel is a shrink fit on the crank, requiring a fair bit of a heat soak to get off if necessary. Best left alone!

 The earlier small journal crank has a much narrower oilway in comparison,  here sludge collects in a cavity under each plug and to echo GB there is no removable tube, it's just a cross drilling. Regular oil changes and a filter in the return line are the way to go for all bikes. Good for keeping the timing bush healthy as well.

 Swarfy.

[RDfella]

Thanks to Andrew for the 'sludge tube' explanation - and Swarfy's wise words re crud collecting outside of the tube - as was evident with mine.
My comments re design remain, however. Who in their right mind would design a service item that requires the engine to be removed and completely stripped in order to access? And one that includes a considerable gallery which in turn means the big ends run dry on start up whilst the oil pump fills the chamber? Must be the same bloke who decided a total engine strip was required to access the oil pump non-return valve (when that on the singles can be serviced in a minute or two).
Compare that sludge tube with a car I recall from the 60's (Fiat if my memory serves) which had a sludge trap instead of an oil filter. To service it took about two minutes, simply requiring half a dozen screws to be undone so a small alloy disc could be removed from the crankshaft pulley.